Actuating mechanism applicable to vehicle brakes



July 26, 1949, H. sHELToN 2,477,458

ACTUATING MECHANISM APPLICABLE T0 VEHICLE BRAKES Filed Feb. 28, 1947 2sheets-sheet 1 v July l2, 1949. H. sHELToN 2.477.458 .ACTUATNG MECHANISMAPPLICABLE TO VEHICLE BRAKES Filed Feb. 28, 1947 2 Sheets-Sheet 2 i @y Ivoir or tank 42a a non-return valve 421) being provided in the pipebetween the reservoir and the engine. The intake valve leads to atmosphere.

The oiitake valve designated generally by reference numeral 42 (Figure2) compr1ses a passage-way 43 connected to the upper end of the cylinder36 and having a port 44 normally closed by valve 45. The valve iscarried by rod 45 secured to spring-loaded armature 41 which is disposedpartly within solenoid 48. One end of spring 45 is disposed within arecess in the armature 41 and the other end engages a pole piece 50which is energised by Solenoid 45. A contact armV 5I, the upper end ofwhich is in electrical connection with the solenoid 48, is pro vidednear its lower end with a contact point 52 which is adapted to engage anadjacent contact point 53 mounted on a bracket 54. A spring member 55presses the contact arm 5I to the left and thus normally maintains thepoints 52, 53 closed. The upper end of the contact arm 5i is inelectrical connection with the Contact 2| in the insulated mounting 22and the bracket 54 is in electrical connection with the springloadedcontact 25. Terminal 6I which is in elec trical connection with thesolenoid 48, is also connected to a battery (see Figure 6)'. A groundedcondenser 48h is provided in the circuit between the points `52, 53 andcontact 25 and a grounded condenser 48C in the circuit between thecontact arm 5I and contact 2l. The lower end of the contact arm5l isprovided with ari' adjustable screw 5Icll -which engages the end of aspring-loaded piston rod 56. which slides within cylinder 58 is securedon one side to piston rod V56, and a valve `59 which is adapted to closethe passageway 43 is seciued to the other side of the piston 51. Aspring Se normally forces the piston rod 56 towards the left,thus'maintainingtheV points 52, 53 closed and the passageway 43 open.The pressure of the spring 6U canbe adjusted by means of a screw 65a onthe rod 56. i

The intakevalve designated generally by the reference 62 comprises ahousing 63 within which is mounted a solenoid 64 and a co-acting springloaded armature 65 to which is secured a valve 56 by means of rod 61.The valve 66 is adapted to normally close port 68 by reason of thepressure of spring 69. An air-inlet passagel@ opens into recess 1I andis provided with a metering screw 12. One lead from the solenoid 64 iscon nected to the contact I9 and the other lead is connected to thebattery.4 A grounded condenser 45a is provided in the circuit betweenthe solenoid 64 and the contact I9. Y Y

An air inlet 12a is provided in the upper wall of the cylinder 38. andisprovided with a springloadedvalve 13 which is adapted to be manuallyraised by means of a bell crank 14 connected to a rod 15. The latter isfitted with a knob 16 or the like which when pulled outwardly, raisesthe valve 13. The rod l.may alternatively be connected to thethrottlelever linkage.

The interior of the cylinder 38 is connected by means of a tube 11 witha cylinder 18 (Figure 1) which is secured on the steering column casingI2 by'bracket 1 9. A diaphragm 85 is dis posed in the cylinder. 15 andis connected to a spring-loaded rod 8I which is pivoted on the curvedarm 26. The pressure of the spring may be adjusted by means of a nut 82threaded on the rod BI. Y f

The piston 51 The operation of the brake-actuating mechanism is asfollows:

To apply the brakes, the control ring I is slightly depressed againstthe pressure oi the spring 25a. When the ring I is depressed, thetelescopic spokes 3 are pivoted downwardly on the pins i6. This downwardpivoting movement is transmitted through the pins "I3 tothe links Iiiwhich are thus depressed. The downward movrn ment of the links I0 lowersthe annular member l I, the sleeve I1 and the annular contact I8 untilthe latter touches the upwardly extending contact 20 in the insulatedmounting 22. This energises the solenoid 48 in the offtake valve 42 ofthe vacuum cylinder 38 and causes the armature 41 and valve 45 to movetowards the left, thus opening the port 44. Suction is then applied tothe interior of cylinder 38 which causes the piston 31 to move upwardlytherein, thus actuating the foot brake through chain 34. The movement ofthe foot pedal lever 29, displaces the rod 28 to the right and thecap'32 engages the curved arm 26 and displaces the upper end thereoftowards the right. This movement causes the link rod 25 to movedownwardly and the insulated mounting is accordingly lowered, thusbreaking the contact between the annular contact I8 and the contact 20.The solenoid 48 is de-energised and the valve 45 moves to the right,thus closing the port 44. The piston 31 and brake mechanism areaccordingly held stationary and the brakes will only be applied morermly if the ring I is further depressed. For each slightfurther-depression of the ring, this series of operations is repeated insuccession.

As will be seen from Figure 1, there is a certain amount of lost motionbefore the curved arm 25 is displaced by the cap 32 and this amount canbe decreased by screwing nut 3U towards the right and increased byscrewing the nut in the opposite direction.

when the soienoid 4s is energised, and the port 44 opened as.hereinbeiore described, the pole piece 55 is also energised and attractsthe Contact arm 5I Vagainst the pressure of spring 55, thus breaking thepoints 52, r53. The solenoid is accordingly de-energisedrand'the spring49 displaces the armature 41 and valve 45 to the right, thus tending toVclose the port 44. On breaking of the points, the Vpole piece 50 isdeenergised and this allows the contacts 52, 53 to close again bypressureof spring 55. Thus a series of rapid oscillations ofthe valve 45is set up while the ring I is being depressed and these oscillationsproduce a smoothness in the braking effect. The valve 53 isl displacedto the right when suction is applied and tends to close the passageway.43 and reduce the suction. This lbrings about an increase in thefrequency in the opening and closing of theport 44 and produces afurther increase in smoothness and sensitivity of the mechanism. Whenthe valve 59 is in its normal position, the piston rod'56 acts againstthe screw 5Ia attached Yto the lower end of the contact arm 5I, andmaintains the points 52, 5 3 closed. When thefpressure in the cylinder38 is reduced, the valve 59 moves to the right and allows the contactarm y5I to oscillate as hereinbefore described. This ensures thatoscillation does not commence until a predetermined reduction inpressure has been eiected.

When the desired braking power has .been reached, downward pressure onthe ring I is discontinued and the ring is held stationary. On th1soccurring, the break between the annular contact` t8; and the contactr2!) :is lat: eftectivefand lthegresultant break in the electricalcircuit causes the orf .take porttouemainxcloscd and thef piston tobeheldfstati'onary the: cylinder. Thismaintainsthe braking-.pressurecon.u starrt: 1

When it is: desired. to release the brakes, the ring. released4 andallowed` toi return' to: its original: position. This raisesv the iannular; con@- tact l 8, causing. it to contact `the A upperfcontactIll-and thereby closethe circuit thezsolenoid E54V controlling the port.of `thevintake4 vaivev E2 off theivacuum cylinder 3.8. :When`thesolenoid iis energisedthe armature 55 andfvalvei Solare displaced to'the.` right thus; openinga the. port.` 65 and allou'ling.L air to enterthe. cylinder through the passa-ge .70.- This allows the: pistoni .elito return: to its original: position; thereby releasingthebrakesi Whenthei port 44 is opened and suction-ap-T plied to the cylinder .38,suction is also" pro duced'` ini the cylindt-:rv .78 thus. causing thecen.- tral portioriV oit the diaphragm ellto bendisplaced to 'the right.causes the rodi `llt and: the linkiro'd .25.' to move accordingly andtends to pull the contact 2l) away from the annular con tact I8. As thediaphragm 80 is very sensitive tochanges in pressure, ,the reaction isvery rapid and so the oscillating movements set up are of highfrequency. This further ensures great smoothness and` sensitivity in theoperation of the brakes. i

In case of failure of the nia-in. circuit `which includes thespring-loadedpontact 20, the ,einern gency circuit which includes thecontact 2| will operate the brakes when the ring l is depressed so thatthe annular contact I8 engages the contact 2|. The latter is connecteddirectly to the solenoid 48 and the latter will be energised when thecontacts I8, 2| are engaged. The mechanism in this case functions aspreviously described except that the points 52, 53 do not form part ofthe circuit.

In case of failure of the intake valve 62 the brakes may be released byopening the valve 'I3 by means of knob 'I6 on the dash board. If thevalve 13 is connected with the throttle lever when the throttle isopened.

The provision of a reserve tank or reservoir f between the engine andthe vacuum cylinder allows the brakes to be applied in an emergencyafter the engine has ceased running, for eX- ample in the event ofstalling. The number of times the brakes can be applied by this meansdepends on the capacity of the reservoir.

The location of the ring I allows it to be conveniently operated bymeans of the thumb or thumbs while the hands are on the steering wheelin the normal position. If one side only of the ring is depressed, thetelescopic construction of the spokes allows the side which is depressedto be lowered to a greater extent than the other side, thus avoiding atendency to jamming of the ring.

The contacts I8, I9, 2B, 2l function eiliciently over long periodswithout cleaning, as the annular contact I8 is rotated with the steeringwheel and if the brakes are applied as the steering wheel is beingturned, the contacts are automatically cleaned by the relative movementbetween them.

lIn the description and claims, the phrases referring to applying orreleasing the brakes is intended to include, where applicable, the mean-`ing; fincreasesfor `decreases the degreefvofi appllcationofthebnakesa qt l Ifclaimf:

`11. In .a1 vehicle,` brakefactuating. mechanism comprisinga source of:suctionagbrake pedal', a cylinder connected with theascurcc ofi suctionyapistonfin the cylinder inoperative connection with the `brake pedal ofthervehicle, oppostely disposed; rigidlyconnected'` members meenam@-callyccmnected to the brake pedal, inanualiy opferable, means. a controlmember mechanically connected to: the manually operable means;V thecontrol member being adapted :to beinoyed into engagement with onev otthe .first-mentioned members by movementin` one direction, ofi.` themanuallyoperable ,means in order to apply the braken and. the controlmember being adapted to be movedlinto-=engagement with the other oitheiirst -mentioned members;bymovementin the other` direction-of themanually operable `means in orden to release the brakes, the movementofthe. brakev pedal in either direction causing the nest-mentioned membersto;` be moved in the same direction:- as l that in which the control member was moved, thus tending to. rez-establish `the previous relativepositions or the said members.

2., In a vehicle, brake-actuating `mechanism comprising a source ofvsuction, a brakepedal, a cylinder connected with the source of suction,va piston. in the cylinder operative. connection with the` brakepedalcfthe; vehicle, the-brakes being adapted. to. bev applied when suctionis an plied to said, cylinder, l intake and -oitake valves for saidcylinder, a pair or oppositely disposed electrical contacts, a singlemounting for said contacts mechanically connected to the brake pedal, amanually operable ring member adjacent the steering wheel of thevehicle, an electrical contact mechanically connected to said ring,means electrically operable to open said oitake valve, a circuitincluding said electrically operable means and one of thefirst-mentioned contacts, means electrically operable to open saidintake valve, a circuit including the second-mentioned electricallyoperable means and the other of the first-mentioned contacts, thesecond-mentioned contact being adapted to be moved into engagement withone of the first-mentioned contacts by movement of the said ring,thereby closing the circuit containing the oiftake valve and causing theoitake valve to be opened and suotion to be applied to said cylinder,the movement of the brake pedal causing the first-mentioned contacts tobe moved in the same direction as that in which the second-mentionedcontact was moved in order to open the offtake valve, thus tending to1re-establish the previous relative positions of the said contacts, thesecond-mentioned contact also being adapted to be moved into engagementwith the other of the rst-mentioned contacts by movement of the saidring, thereby closing the circuit containing the intake valve andcausing the intake valve to be opened and the brakes to be released.

3. In a Vehicle, brake-actuating mechanism according to claim 2, aplurality of contacts on said mounting means adjacent to each other,each contact being electrically connected to the means electricallyoperable to open the offtake valve.

1. In a vehicle, brake-actuating mechanism according to claim 2,telescopic spokes and link mechanism which is capable of movementrelative to the spokes connecting said ring to said second-mentionedcontact.

5. In a vehicle, brake-actuating mechanism according to claim 2, anormally closed manually operable air-inlet valve in said cylinder. I

6. In a Vehicle, brake-actuating mechanism comprising a source ofsuction, a brake pedal, a cylinder connected with the source of suction,a piston in the cylinder in operative connection with the brake pedal ofthe vehicle, the brakes being adapted to be applied when suction isapplied to said cylinder, intake and oitake valves for said cylinder,oppositely disposed rigidlyconnected members mechanically connected tothe brake pedal, manually operable means, a control member mechanicallyconnectedV to the manuallyV operable means, the control member 'beingadapted to be moved into engagement with one of the first-mentionedmembers by movement in one direction of the manually operable means inorder to open the said oiitake valve and apply the brakes, and thecontrol member being adapted to be moved into engagement with the otherof the first-mentioned members by movement in the other direction of themanually operable means in order to open the said intake valve andrelease the brakes, the movement of the brake pedal in either directioncausing the first-mentioned members to be moved in the same direction asthat in which the control member was moved, thus tending torre-establishthe previous relative positions of the said members.

7. In a vehicle, brake-actuating mechanism comprising a source ofsuction, a brake pedal, a cylinder connected with the source of suction,a piston in the cylinder in operative connection with the brake pedal ofthe vehicle, the brakes le of this patent:

8 being adapted to be applied whensuction is applied to said cylinder,intake and oitake valves for said cylinder, cppositely disposedrigidlyconnected electrical contacts mechanically con-V nected to thebrake pedal, manually operable means, an electrical contact mechanicallyconnected to the manually operable means, the second mentionedelectrical contact being adapted to be moved into engagement with one ofthe rstmentioned electrical contacts by movement in one direction of themanually operable means in order to openthe said oitake valve and applythe brakes, and the second-mentioned electrical contact being adapted tobe moved into engagement with the other of the mst-mentioned electricalcontacts by movement in the other direction of the manually operablemeans` in order to open the said intake valve and release the brakes,the movement of the brake pedal in either direction causing theiirst-mentioned electrical contacts to be moved in the same direction asthat in which the second-mentioned electrical contact was moved, thustending to re-establish the previous relative positions of the saidelectrical contacts. HAROLD SHELTON.

REFERENCES CITED The following referenlces are of record in the UNITEDSTATES PATENTS Number Name Date 1,857,053 Kratz May 3, 1932- 1,878,822Dewandre Sept. 20, 1932

